HARNESS AS-SWITCH 1605574 - Caterpillar

Because of the differences in piston design:
... Installation of "wide taper" rod assemblies as a replacement for "straight side" rod assemblies will not give all the advantages of the design. The reason for this is that the pistons for the "straight side" rods do not have the added bearing area around the piston pin.... The "wide taper" rod assemblies can be installed in place of "straight side" rod asemblies, but not in place of "narrow taper" rod assemblies. This is the reason for use of 8N1728 Connecting Rod Assemblies as a replacement for the canceled 4N390 Connecting Rod Assemblies in earlier 3408 Engines with precombustion chambers (PC), but not in later 3408 Engines (PC). The later 3408 Engines (PC) use "narrow taper" rod assemblies. Only the 3408 Engines with direct injection (DI) have pistons for the 8N1728 Connecting Rod Assemblies.In the identification of connecting rods, be sure to use the assembly part number which is put on the bottom of the connecting rod cap with a 3.18 mm (.12") high stamp. Do NOT use the forging number which is shown on one side of the center section of the rod. Since the same forging is used to make different connecting rod assemblies, use of the forging number as a reference can cause errors.